"Justice is served!" This signature phrase of the Scourge of the Underworld would strike fear in the hearts of super criminals throughout the nation, as it signaled that yet another super-villain was killed by a mysterious vigilante.

It was first uttered upon the assassination of the criminal Enforcer, when a homeless lady interrupted the Enforcer’s own mission to assassinate the Termite, surprisingly and suddenly striking him down. One by one, other costumed super-villains were murdered. The Miracle Man was killed by a man riding a bus, the android Hate-Monger was shot by a pedestrian, Megatek was murdered by another homeless person, and the Melter was killed by a man posing as his assistant . . . nowhere seemed safe as the Scourge appeared in different guises, revealing himself only after shooting his victim. In fact, a female pro-wrestler, Golddigger, revealed herself as the Scourge, shooting an unsuspecting Titania while she showered. A male nurse shot at the Constrictor, who survived, but a construction worker shot dead the Basilisk, a Native American shot Hammer and Anvil, and the Fly was shot by a garbage man, the Wraith by a police officer. More murders: the Death Adder was killed by a cab driver, Blue Streak by a truck driver, both after fleeing a battle with Captain America. And after each hit, the phrase "justice is served!"

The Water Wizard was particularly distraught at the massacre, one he missed by arriving late, and he sought out Captain America for help. Captain America disguised himself as the Scourge's recent victim, Mirage, in order to draw him out, and succeeded. The Scourge tried to assassinate him, but the Captain turned the tables on him. He captured and unmasked the Scourge, who confessed to being the brother of the Enforcer, his first victim. However, before Captain America could apprehend him, his captive was shot by an unseen assassin, who uttered the words "justice. . . is served!"

In fact, the Scourge of the Underworld was not one person, but the name adopted by various agents of a mysterious organization which funded, trained, and deployed its agents for acts of vigilantism, killing known super-criminals. The previous hits were all performed by at least two agents calling themselves Scourge: one male (name unrevealed), one female (later named Caprice).

The organization itself was founded by the Angel, a major hero of the 1940's who retired after an innocent bystander was killed by a criminal he was battling. Consumed by rage and guilt, the Angel used his personal fortune to create the Scourge of the Underworld, dedicating it to the permanent termination of super-villains. He also recruited information specialist Domino Dunsinane, to track the activities of potential targets, and the vigilante Bloodstain, to train prospective field agents. Scourge operatives are well-trained before they deploy, studying infiltration, disguise, and role-playing techniques, as well as marksmanship and advanced training in hand-to-hand combat. The standard armament of a Scourge is a .50 caliber Thompson machine gun with a sawed-off barrel and stock, using instead a folding wire stock and a special 5-round clip filled with acceleration-activated, delay-triggered explosive bullets.

The Red Skull had also claimed to be a secret founder, or at least a major financial contributor, to the organization, having at least one agent operating as the Scourge on his behalf. However, this Scourge was a rogue agent from the original organization. He killed the Skull's successor, posing as his helicopter pilot, and battled the U.S.Agent, then Captain America, with other agents of the Skull. Other kills performed by this Scourge include the Black Abbott, Lionfang, and the Wrench, but his failure to kill such minor threats as the Shocker, Gamecock and Steelwind prompted the Red Skull to dismiss him, killing him with his dust of death.

The Scourge then set its sights on the Power Broker, killing all of his staff within his mansion. The government determined to place the Broker in protective custody, ordering the U.S.Agent (as Captain America) to defend him and to apprehend the Scourge, still believed to be a single person. The Power Broker was defended by both the Agent and Vagabond, the latter who was on hand because she wanted to use the Broker’s technology to gain superpowers. The Broker turned his technology on himself, however, hoping to gain powers to defend against the Scourge, only to find the process rendered him immobile. U.S.Agent managed to defeat the Scourge, but, as before, he was killed by another Scourge agent before he could be turned over to custody.

Vagabond was then contacted to become a Scourge agent herself, although she was led to believe that she was joining a secret superhero training program. She discovered the truth after shadowing a fellow agent (known as Decker) and seeing him kill an unknown costumed villain. Already doubting the organization’s motives, she tried to assassinate the Matador but chose instead to abandon the group, fleeing after seeing the Matador as a person, a babysitter with his sister’s children. She managed to get help from the U.S.Agent, who met with her and followed a Scourge agent that tried to kill her for defecting. The Agent disguised himself as the Scourge member, infiltrating the organization, although he was quickly discovered, captured, and tortured.

Determined to recover their two missing agents, the leaders of the Scourge organization led the U.S.Agent to believe that Bloodstain was in fact his brother and offered him a place in the group. Bloodstain and Caprice released him and followed him back to the captive Scourge and Vagabond, hoping to kill them all. During the battle, the captive Scourge was shot and killed, and Caprice was accidentally shot and captured. Bloodstain escaped, but the U.S.Agent was able to track him down to the Angel’s mansion. Finally confronting the head of the Scourge organization, the U.S.Agent was able to uncover the truth behind the group. However, he was confronted again by Bloodstain, whose battle frenzy claimed the life of Domino Dunsinane and whose bullets ricocheted off the Agent’s shield, killing himself. The Angel was left with no agents, and the U.S.Agent remanded him to the authorities so that justice, finally, might be truly served.

Note: Years later, Nomad (Jack Monroe) was used by Henry Peter Gyrich, head of the Commission on Superhuman Activities and outfitted with the costume and identity of Scourge in reminiscence of the agents of the original organization. Monroe, as Scourge, was charged with the task to hunt down and eliminate the members of the team Thunderbolts, although the team eventually managed to defeat Scourge, revealing him to be Monroe and that Gyrich hoped to use the destructive power of nanoprobes to wipe out all superhumans on Earth. The Thunderbolts ultimately discovered that Gyrich himself was being controlled by the nanoprobes, and they freed everyone from the thrall of the nanotech.